Complete mandibular agenesis. Report of a case.

A child had complete mandibular agenesis, with associated anomalies of microstomia, left choanal stenosis, and a cleft soft palate. This child had evidence of disruption in development at about the four-week stage by the persistence of several developmental remnants, specifically, the buccopharyngeal membrane, tongue remnants, and the laryngotracheal groove. The etiology of this condition is unclear at this time.